Diamagnetic and Paramagnetic Effects
This chapter discusses the concepts of paramagnetism and diamagnetism to provide a basis for additional understanding of electron behavior in solids. One way to describe the behaviors of materials in magnetic fields is to categorize them on the bases of the magnitude, sign, and effect of temperature of their magnetic properties. Many materials show a very small magnetic susceptibility. It is composed of a diamagnetic part and a paramagnetic part. Diamagnetism arises from the changes of the "orbital" axes of the electrons of an ion in an applied magnetic field. Paramagnetism results from some degree of alignment of the permanent ionic dipoles within a substance; this gives a positive susceptibility. Transition and rare-earth elements and their compounds show very pronounced paramagnetic behaviors. A simple way to discriminate between diamagnetic and paramagnetic materials is to place them in a nonuniform magnetic field.